20 BULLETIN 892, U. §. DEPARTMENT OF AGRICULTURE. 
No. 9. Paris green, 2 pounds, and whale-oil soap, 3 pounds, to 50 
gallons. : 
No. 10. Arsenate of lead, 3 pounds, and laundry soap, 3 pounds, to 
50 gallons. 
No. 11. Arsenate of lead, 3 pounds, and Paris green, 4 pound, to 50 
gallons. 
No. 12. Arsenate of lead, 5 pounds to 50 gallons. ~~ 
No. 18. Arsenate of lead, 5 pounds, and Paris green, 1 pound, to 50 
gallons. 
No. 14. Arsenate of lead, 5 pounds, and lime-sulphur solution, 2 
gallons, to 50 gallons. 
No. 15. Zine arsenite, 24 pounds, and Paris green, 4 pound, to 50 
gallons. 
No. 16. Zine arsenite, 2 pounds, and whale-oil soap, 3 pounds, to 
50 gallons. 
No. 17. Zine arsenite, 24 pounds, and whale-oil soap, 243 pounds, to 
50 gallons. 
Dusting experiments. 
No. 18. Paris green, 1 pound to 50 pounds of fleur. 
No. 19. Paris green, 2 pounds to 50 pounds of flour. 
No. 20. Paris green, 5 pounds to 50 pounds of flour. 
No. 21. Paris green, 1 pound to 50 pounds of wood ashes. 
No. 22. Paris green, 2 pounds to 50 pounds of wood ashes. 
Several additional experiments were made, especially with lead 
chromate at rates varying from about $ pound to 3 pounds in 50 gal- 
lons of water, but this substance proved to be utterly worthless éither 
as a stomach poison or as a repellent against this insect. The same 
is true in its application against most other forms of insect pests. 
In the course of these experiments more than 60 acres of sugar 
beets were sprayed or dusted. With the spraying experiments pre- 
liminary tests were made with knapsack sprayers, and the poisons 
which gave promise of being successful were later tried out on a 
larger scale with field sprayers. The “dust” was applied with a 
“powder gun” or was shaken upon the foliage from cheesecloth 
sacks. 
Without exception the poisons tested in the foregoing experiments 
proved unsatisfactory against the adults but in most cases were 
partially or wholly effective against the larve. The failure to con- 
trol the beetles was due to the fact that, as a rule, they refused to 
eat the poisoned foliage except when no other food was available. 
All the poisons, except lead chromate, killed the beetles whenever 
eaten. Usually, however, the beetles promptly deserted the treated 
plants but returned after the poison was washed away or blown 
from the foliage or after new leaves developed. The poisons were 
usually effective as repellents for’ periods of from 2 to 5 days. 
The poisons with which whale-oil soap or lime-sulphur solution 
were used served as repellents for longer periods than when applied 
